Having a single way to authenticate can help save your business time and money as well as eliminate the annoyance of having to maintain numerous accounts for any given individual in a company. Concrete5 has the ExchangeCore LDAP package to meet that need in environments that have an LDAP server available. And we've shown here, how to set up it in step by step.
AWS's Elastic Load Balancing distributes incoming application traffic across multiple EC2 instances, in multiple Availability Zones. This increases the fault tolerance and performance of your applications. It works fine with Symfony (popular php framework). But you may get error when you run your Symfony application behind AWS Elastic Load Balancer System with HTTPS connection. If so, this may save your time.